hw/watchdog/wdt_aspeed.c - qemu - Git at Google

 /*
  * ASPEED Watchdog Controller
  *
  * Copyright (C) 2016-2017 IBM Corp.
  *
  * This code is licensed under the GPL version 2 or later. See the
  * COPYING file in the top-level directory.
  */

 #include "qemu/osdep.h"

 #include "qapi/error.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
 #include "qemu/timer.h"
 #include "sysemu/watchdog.h"
 #include "hw/qdev-properties.h"
 #include "hw/sysbus.h"
 #include "hw/watchdog/wdt_aspeed.h"
 #include "migration/vmstate.h"
 #include "trace.h"

 #define WDT_STATUS                      (0x00 / 4)
 #define WDT_RELOAD_VALUE                (0x04 / 4)
 #define WDT_RESTART                     (0x08 / 4)
 #define WDT_CTRL                        (0x0C / 4)
 #define   WDT_CTRL_RESET_MODE_SOC       (0x00 << 5)
 #define   WDT_CTRL_RESET_MODE_FULL_CHIP (0x01 << 5)
 #define   WDT_CTRL_1MHZ_CLK             BIT(4)
 #define   WDT_CTRL_WDT_EXT              BIT(3)
 #define   WDT_CTRL_WDT_INTR             BIT(2)
 #define   WDT_CTRL_RESET_SYSTEM         BIT(1)
 #define   WDT_CTRL_ENABLE               BIT(0)
 #define WDT_RESET_WIDTH                 (0x18 / 4)
 #define   WDT_RESET_WIDTH_ACTIVE_HIGH   BIT(31)
 #define     WDT_POLARITY_MASK           (0xFF << 24)
 #define     WDT_ACTIVE_HIGH_MAGIC       (0xA5 << 24)
 #define     WDT_ACTIVE_LOW_MAGIC        (0x5A << 24)
 #define   WDT_RESET_WIDTH_PUSH_PULL     BIT(30)
 #define     WDT_DRIVE_TYPE_MASK         (0xFF << 24)
 #define     WDT_PUSH_PULL_MAGIC         (0xA8 << 24)
 #define     WDT_OPEN_DRAIN_MAGIC        (0x8A << 24)
 #define WDT_RESET_MASK1                 (0x1c / 4)
 #define WDT_RESET_MASK2                 (0x20 / 4)

 #define WDT_SW_RESET_CTRL               (0x24 / 4)
 #define WDT_SW_RESET_MASK1              (0x28 / 4)
 #define WDT_SW_RESET_MASK2              (0x2c / 4)

 #define WDT_TIMEOUT_STATUS              (0x10 / 4)
 #define WDT_TIMEOUT_CLEAR               (0x14 / 4)

 #define WDT_RESTART_MAGIC               0x4755

 #define AST2600_SCU_RESET_CONTROL1      (0x40 / 4)
 #define SCU_RESET_CONTROL1              (0x04 / 4)
 #define    SCU_RESET_SDRAM              BIT(0)

 static bool aspeed_wdt_is_enabled(const AspeedWDTState *s)
 {
     return s->regs[WDT_CTRL] & WDT_CTRL_ENABLE;
 }

 static uint64_t aspeed_wdt_read(void *opaque, hwaddr offset, unsigned size)
 {
     AspeedWDTState *s = ASPEED_WDT(opaque);

     trace_aspeed_wdt_read(offset, size);

     offset >>= 2;

     switch (offset) {
     case WDT_STATUS:
         return s->regs[WDT_STATUS];
     case WDT_RELOAD_VALUE:
         return s->regs[WDT_RELOAD_VALUE];
     case WDT_RESTART:
         qemu_log_mask(LOG_GUEST_ERROR,
                       "%s: read from write-only reg at offset 0x%"
                       HWADDR_PRIx "\n", __func__, offset);
         return 0;
     case WDT_CTRL:
         return s->regs[WDT_CTRL];
     case WDT_RESET_WIDTH:
         return s->regs[WDT_RESET_WIDTH];
     case WDT_RESET_MASK1:
         return s->regs[WDT_RESET_MASK1];
     case WDT_TIMEOUT_STATUS:
     case WDT_TIMEOUT_CLEAR:
     case WDT_RESET_MASK2:
     case WDT_SW_RESET_CTRL:
     case WDT_SW_RESET_MASK1:
     case WDT_SW_RESET_MASK2:
         qemu_log_mask(LOG_UNIMP,
                       "%s: uninmplemented read at offset 0x%" HWADDR_PRIx "\n",
                       __func__, offset);
         return 0;
     default:
         qemu_log_mask(LOG_GUEST_ERROR,
                       "%s: Out-of-bounds read at offset 0x%" HWADDR_PRIx "\n",
                       __func__, offset);
         return 0;
     }

 }

 static void aspeed_wdt_reload(AspeedWDTState *s)
 {
     uint64_t reload;

     if (!(s->regs[WDT_CTRL] & WDT_CTRL_1MHZ_CLK)) {
         reload = muldiv64(s->regs[WDT_RELOAD_VALUE], NANOSECONDS_PER_SECOND,
                           s->pclk_freq);
     } else {
         reload = s->regs[WDT_RELOAD_VALUE] * 1000ULL;
     }

     if (aspeed_wdt_is_enabled(s)) {
         timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + reload);
     }
 }

 static void aspeed_wdt_reload_1mhz(AspeedWDTState *s)
 {
     uint64_t reload = s->regs[WDT_RELOAD_VALUE] * 1000ULL;

     if (aspeed_wdt_is_enabled(s)) {
         timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + reload);
     }
 }

 static uint64_t aspeed_2400_sanitize_ctrl(uint64_t data)
 {
     return data & 0xffff;
 }

 static uint64_t aspeed_2500_sanitize_ctrl(uint64_t data)
 {
     return (data & ~(0xfUL << 8)) | WDT_CTRL_1MHZ_CLK;
 }

 static uint64_t aspeed_2600_sanitize_ctrl(uint64_t data)
 {
     return data & ~(0x7UL << 7);
 }

 static void aspeed_wdt_write(void *opaque, hwaddr offset, uint64_t data,
                              unsigned size)
 {
     AspeedWDTState *s = ASPEED_WDT(opaque);
     AspeedWDTClass *awc = ASPEED_WDT_GET_CLASS(s);
     bool enable;

     trace_aspeed_wdt_write(offset, size, data);

     offset >>= 2;

     switch (offset) {
     case WDT_STATUS:
         qemu_log_mask(LOG_GUEST_ERROR,
                       "%s: write to read-only reg at offset 0x%"
                       HWADDR_PRIx "\n", __func__, offset);
         break;
     case WDT_RELOAD_VALUE:
         s->regs[WDT_RELOAD_VALUE] = data;
         break;
     case WDT_RESTART:
         if ((data & 0xFFFF) == WDT_RESTART_MAGIC) {
             s->regs[WDT_STATUS] = s->regs[WDT_RELOAD_VALUE];
             awc->wdt_reload(s);
         }
         break;
     case WDT_CTRL:
         data = awc->sanitize_ctrl(data);
         enable = data & WDT_CTRL_ENABLE;
         if (enable && !aspeed_wdt_is_enabled(s)) {
             s->regs[WDT_CTRL] = data;
             awc->wdt_reload(s);
         } else if (!enable && aspeed_wdt_is_enabled(s)) {
             s->regs[WDT_CTRL] = data;
             timer_del(s->timer);
         } else {
             s->regs[WDT_CTRL] = data;
         }
         break;
     case WDT_RESET_WIDTH:
         if (awc->reset_pulse) {
             awc->reset_pulse(s, data & WDT_POLARITY_MASK);
         }
         s->regs[WDT_RESET_WIDTH] &= ~awc->ext_pulse_width_mask;
         s->regs[WDT_RESET_WIDTH] |= data & awc->ext_pulse_width_mask;
         break;

     case WDT_RESET_MASK1:
         /* TODO: implement */
         s->regs[WDT_RESET_MASK1] = data;
         break;

     case WDT_TIMEOUT_STATUS:
     case WDT_TIMEOUT_CLEAR:
     case WDT_RESET_MASK2:
     case WDT_SW_RESET_CTRL:
     case WDT_SW_RESET_MASK1:
     case WDT_SW_RESET_MASK2:
         qemu_log_mask(LOG_UNIMP,
                       "%s: uninmplemented write at offset 0x%" HWADDR_PRIx "\n",
                       __func__, offset);
         break;
     default:
         qemu_log_mask(LOG_GUEST_ERROR,
                       "%s: Out-of-bounds write at offset 0x%" HWADDR_PRIx "\n",
                       __func__, offset);
     }
     return;
 }

 static const VMStateDescription vmstate_aspeed_wdt = {
     .name = "vmstate_aspeed_wdt",
     .version_id = 0,
     .minimum_version_id = 0,
     .fields = (const VMStateField[]) {
         VMSTATE_TIMER_PTR(timer, AspeedWDTState),
         VMSTATE_UINT32_ARRAY(regs, AspeedWDTState, ASPEED_WDT_REGS_MAX),
         VMSTATE_END_OF_LIST()
     }
 };

 static const MemoryRegionOps aspeed_wdt_ops = {
     .read = aspeed_wdt_read,
     .write = aspeed_wdt_write,
     .endianness = DEVICE_LITTLE_ENDIAN,
     .valid.min_access_size = 4,
     .valid.max_access_size = 4,
     .valid.unaligned = false,
 };

 static void aspeed_wdt_reset(DeviceState *dev)
 {
     AspeedWDTState *s = ASPEED_WDT(dev);
     AspeedWDTClass *awc = ASPEED_WDT_GET_CLASS(s);

     s->regs[WDT_STATUS] = awc->default_status;
     s->regs[WDT_RELOAD_VALUE] = awc->default_reload_value;
     s->regs[WDT_RESTART] = 0;
     s->regs[WDT_CTRL] = awc->sanitize_ctrl(0);
     s->regs[WDT_RESET_WIDTH] = 0xFF;

     timer_del(s->timer);
 }

 static void aspeed_wdt_timer_expired(void *dev)
 {
     AspeedWDTState *s = ASPEED_WDT(dev);
     uint32_t reset_ctrl_reg = ASPEED_WDT_GET_CLASS(s)->reset_ctrl_reg;

     /* Do not reset on SDRAM controller reset */
     if (s->scu->regs[reset_ctrl_reg] & SCU_RESET_SDRAM) {
         timer_del(s->timer);
         s->regs[WDT_CTRL] = 0;
         return;
     }

     qemu_log_mask(CPU_LOG_RESET, "Watchdog timer %" HWADDR_PRIx " expired.\n",
                   s->iomem.addr);
     watchdog_perform_action();
     timer_del(s->timer);
 }

 #define PCLK_HZ 24000000

 static void aspeed_wdt_realize(DeviceState *dev, Error **errp)
 {
     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
     AspeedWDTState *s = ASPEED_WDT(dev);
     AspeedWDTClass *awc = ASPEED_WDT_GET_CLASS(dev);

     assert(s->scu);

     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, aspeed_wdt_timer_expired, dev);

     /* FIXME: This setting should be derived from the SCU hw strapping
      * register SCU70
      */
     s->pclk_freq = PCLK_HZ;

     memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_wdt_ops, s,
                           TYPE_ASPEED_WDT, awc->iosize);
     sysbus_init_mmio(sbd, &s->iomem);
 }

 static Property aspeed_wdt_properties[] = {
     DEFINE_PROP_LINK("scu", AspeedWDTState, scu, TYPE_ASPEED_SCU,
                      AspeedSCUState *),
     DEFINE_PROP_END_OF_LIST(),
 };

 static void aspeed_wdt_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);

     dc->desc = "ASPEED Watchdog Controller";
     dc->realize = aspeed_wdt_realize;
     dc->reset = aspeed_wdt_reset;
     set_bit(DEVICE_CATEGORY_WATCHDOG, dc->categories);
     dc->vmsd = &vmstate_aspeed_wdt;
     device_class_set_props(dc, aspeed_wdt_properties);
     dc->desc = "Aspeed watchdog device";
 }

 static const TypeInfo aspeed_wdt_info = {
     .parent = TYPE_SYS_BUS_DEVICE,
     .name  = TYPE_ASPEED_WDT,
     .instance_size  = sizeof(AspeedWDTState),
     .class_init = aspeed_wdt_class_init,
     .class_size    = sizeof(AspeedWDTClass),
     .abstract      = true,
 };

 static void aspeed_2400_wdt_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     AspeedWDTClass *awc = ASPEED_WDT_CLASS(klass);

     dc->desc = "ASPEED 2400 Watchdog Controller";
     awc->iosize = 0x20;
     awc->ext_pulse_width_mask = 0xff;
     awc->reset_ctrl_reg = SCU_RESET_CONTROL1;
     awc->wdt_reload = aspeed_wdt_reload;
     awc->sanitize_ctrl = aspeed_2400_sanitize_ctrl;
     awc->default_status = 0x03EF1480;
     awc->default_reload_value = 0x03EF1480;
 }

 static const TypeInfo aspeed_2400_wdt_info = {
     .name = TYPE_ASPEED_2400_WDT,
     .parent = TYPE_ASPEED_WDT,
     .instance_size = sizeof(AspeedWDTState),
     .class_init = aspeed_2400_wdt_class_init,
 };

 static void aspeed_2500_wdt_reset_pulse(AspeedWDTState *s, uint32_t property)
 {
     if (property) {
         if (property == WDT_ACTIVE_HIGH_MAGIC) {
             s->regs[WDT_RESET_WIDTH] |= WDT_RESET_WIDTH_ACTIVE_HIGH;
         } else if (property == WDT_ACTIVE_LOW_MAGIC) {
             s->regs[WDT_RESET_WIDTH] &= ~WDT_RESET_WIDTH_ACTIVE_HIGH;
         } else if (property == WDT_PUSH_PULL_MAGIC) {
             s->regs[WDT_RESET_WIDTH] |= WDT_RESET_WIDTH_PUSH_PULL;
         } else if (property == WDT_OPEN_DRAIN_MAGIC) {
             s->regs[WDT_RESET_WIDTH] &= ~WDT_RESET_WIDTH_PUSH_PULL;
         }
     }
 }

 static void aspeed_2500_wdt_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     AspeedWDTClass *awc = ASPEED_WDT_CLASS(klass);

     dc->desc = "ASPEED 2500 Watchdog Controller";
     awc->iosize = 0x20;
     awc->ext_pulse_width_mask = 0xfffff;
     awc->reset_ctrl_reg = SCU_RESET_CONTROL1;
     awc->reset_pulse = aspeed_2500_wdt_reset_pulse;
     awc->wdt_reload = aspeed_wdt_reload_1mhz;
     awc->sanitize_ctrl = aspeed_2500_sanitize_ctrl;
     awc->default_status = 0x014FB180;
     awc->default_reload_value = 0x014FB180;
 }

 static const TypeInfo aspeed_2500_wdt_info = {
     .name = TYPE_ASPEED_2500_WDT,
     .parent = TYPE_ASPEED_WDT,
     .instance_size = sizeof(AspeedWDTState),
     .class_init = aspeed_2500_wdt_class_init,
 };

 static void aspeed_2600_wdt_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     AspeedWDTClass *awc = ASPEED_WDT_CLASS(klass);

     dc->desc = "ASPEED 2600 Watchdog Controller";
     awc->iosize = 0x40;
     awc->ext_pulse_width_mask = 0xfffff; /* TODO */
     awc->reset_ctrl_reg = AST2600_SCU_RESET_CONTROL1;
     awc->reset_pulse = aspeed_2500_wdt_reset_pulse;
     awc->wdt_reload = aspeed_wdt_reload_1mhz;
     awc->sanitize_ctrl = aspeed_2600_sanitize_ctrl;
     awc->default_status = 0x014FB180;
     awc->default_reload_value = 0x014FB180;
 }

 static const TypeInfo aspeed_2600_wdt_info = {
     .name = TYPE_ASPEED_2600_WDT,
     .parent = TYPE_ASPEED_WDT,
     .instance_size = sizeof(AspeedWDTState),
     .class_init = aspeed_2600_wdt_class_init,
 };

 static void aspeed_1030_wdt_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     AspeedWDTClass *awc = ASPEED_WDT_CLASS(klass);

     dc->desc = "ASPEED 1030 Watchdog Controller";
     awc->iosize = 0x80;
     awc->ext_pulse_width_mask = 0xfffff; /* TODO */
     awc->reset_ctrl_reg = AST2600_SCU_RESET_CONTROL1;
     awc->reset_pulse = aspeed_2500_wdt_reset_pulse;
     awc->wdt_reload = aspeed_wdt_reload_1mhz;
     awc->sanitize_ctrl = aspeed_2600_sanitize_ctrl;
     awc->default_status = 0x014FB180;
     awc->default_reload_value = 0x014FB180;
 }

 static const TypeInfo aspeed_1030_wdt_info = {
     .name = TYPE_ASPEED_1030_WDT,
     .parent = TYPE_ASPEED_WDT,
     .instance_size = sizeof(AspeedWDTState),
     .class_init = aspeed_1030_wdt_class_init,
 };

 static void wdt_aspeed_register_types(void)
 {
     type_register_static(&aspeed_wdt_info);
     type_register_static(&aspeed_2400_wdt_info);
     type_register_static(&aspeed_2500_wdt_info);
     type_register_static(&aspeed_2600_wdt_info);
     type_register_static(&aspeed_1030_wdt_info);
 }

 type_init(wdt_aspeed_register_types)
	/*
	* ASPEED Watchdog Controller
	*
	* Copyright (C) 2016-2017 IBM Corp.
	*
	* This code is licensed under the GPL version 2 or later. See the
	* COPYING file in the top-level directory.
	*/

	#include "qemu/osdep.h"

	#include "qapi/error.h"
	#include "qemu/log.h"
	#include "qemu/module.h"
	#include "qemu/timer.h"
	#include "sysemu/watchdog.h"
	#include "hw/qdev-properties.h"
	#include "hw/sysbus.h"
	#include "hw/watchdog/wdt_aspeed.h"
	#include "migration/vmstate.h"
	#include "trace.h"

	#define WDT_STATUS (0x00 / 4)
	#define WDT_RELOAD_VALUE (0x04 / 4)
	#define WDT_RESTART (0x08 / 4)
	#define WDT_CTRL (0x0C / 4)
	#define WDT_CTRL_RESET_MODE_SOC (0x00 << 5)
	#define WDT_CTRL_RESET_MODE_FULL_CHIP (0x01 << 5)
	#define WDT_CTRL_1MHZ_CLK BIT(4)
	#define WDT_CTRL_WDT_EXT BIT(3)
	#define WDT_CTRL_WDT_INTR BIT(2)
	#define WDT_CTRL_RESET_SYSTEM BIT(1)
	#define WDT_CTRL_ENABLE BIT(0)
	#define WDT_RESET_WIDTH (0x18 / 4)
	#define WDT_RESET_WIDTH_ACTIVE_HIGH BIT(31)
	#define WDT_POLARITY_MASK (0xFF << 24)
	#define WDT_ACTIVE_HIGH_MAGIC (0xA5 << 24)
	#define WDT_ACTIVE_LOW_MAGIC (0x5A << 24)
	#define WDT_RESET_WIDTH_PUSH_PULL BIT(30)
	#define WDT_DRIVE_TYPE_MASK (0xFF << 24)
	#define WDT_PUSH_PULL_MAGIC (0xA8 << 24)
	#define WDT_OPEN_DRAIN_MAGIC (0x8A << 24)
	#define WDT_RESET_MASK1 (0x1c / 4)
	#define WDT_RESET_MASK2 (0x20 / 4)

	#define WDT_SW_RESET_CTRL (0x24 / 4)
	#define WDT_SW_RESET_MASK1 (0x28 / 4)
	#define WDT_SW_RESET_MASK2 (0x2c / 4)

	#define WDT_TIMEOUT_STATUS (0x10 / 4)
	#define WDT_TIMEOUT_CLEAR (0x14 / 4)

	#define WDT_RESTART_MAGIC 0x4755

	#define AST2600_SCU_RESET_CONTROL1 (0x40 / 4)
	#define SCU_RESET_CONTROL1 (0x04 / 4)
	#define SCU_RESET_SDRAM BIT(0)

	static bool aspeed_wdt_is_enabled(const AspeedWDTState *s)
	{
	return s->regs[WDT_CTRL] & WDT_CTRL_ENABLE;
	}

	static uint64_t aspeed_wdt_read(void *opaque, hwaddr offset, unsigned size)
	{
	AspeedWDTState *s = ASPEED_WDT(opaque);

	trace_aspeed_wdt_read(offset, size);

	offset >>= 2;

	switch (offset) {
	case WDT_STATUS:
	return s->regs[WDT_STATUS];
	case WDT_RELOAD_VALUE:
	return s->regs[WDT_RELOAD_VALUE];
	case WDT_RESTART:
	qemu_log_mask(LOG_GUEST_ERROR,
	"%s: read from write-only reg at offset 0x%"
	HWADDR_PRIx "\n", __func__, offset);
	return 0;
	case WDT_CTRL:
	return s->regs[WDT_CTRL];
	case WDT_RESET_WIDTH:
	return s->regs[WDT_RESET_WIDTH];
	case WDT_RESET_MASK1:
	return s->regs[WDT_RESET_MASK1];
	case WDT_TIMEOUT_STATUS:
	case WDT_TIMEOUT_CLEAR:
	case WDT_RESET_MASK2:
	case WDT_SW_RESET_CTRL:
	case WDT_SW_RESET_MASK1:
	case WDT_SW_RESET_MASK2:
	qemu_log_mask(LOG_UNIMP,
	"%s: uninmplemented read at offset 0x%" HWADDR_PRIx "\n",
	__func__, offset);
	return 0;
	default:
	qemu_log_mask(LOG_GUEST_ERROR,
	"%s: Out-of-bounds read at offset 0x%" HWADDR_PRIx "\n",
	__func__, offset);
	return 0;
	}

	}

	static void aspeed_wdt_reload(AspeedWDTState *s)
	{
	uint64_t reload;

	if (!(s->regs[WDT_CTRL] & WDT_CTRL_1MHZ_CLK)) {
	reload = muldiv64(s->regs[WDT_RELOAD_VALUE], NANOSECONDS_PER_SECOND,
	s->pclk_freq);
	} else {
	reload = s->regs[WDT_RELOAD_VALUE] * 1000ULL;
	}

	if (aspeed_wdt_is_enabled(s)) {
	timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + reload);
	}
	}

	static void aspeed_wdt_reload_1mhz(AspeedWDTState *s)
	{
	uint64_t reload = s->regs[WDT_RELOAD_VALUE] * 1000ULL;

	if (aspeed_wdt_is_enabled(s)) {
	timer_mod(s->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + reload);
	}
	}

	static uint64_t aspeed_2400_sanitize_ctrl(uint64_t data)
	{
	return data & 0xffff;
	}

	static uint64_t aspeed_2500_sanitize_ctrl(uint64_t data)
	{
	return (data & ~(0xfUL << 8)) \| WDT_CTRL_1MHZ_CLK;
	}

	static uint64_t aspeed_2600_sanitize_ctrl(uint64_t data)
	{
	return data & ~(0x7UL << 7);
	}

	static void aspeed_wdt_write(void *opaque, hwaddr offset, uint64_t data,
	unsigned size)
	{
	AspeedWDTState *s = ASPEED_WDT(opaque);
	AspeedWDTClass *awc = ASPEED_WDT_GET_CLASS(s);
	bool enable;

	trace_aspeed_wdt_write(offset, size, data);

	offset >>= 2;

	switch (offset) {
	case WDT_STATUS:
	qemu_log_mask(LOG_GUEST_ERROR,
	"%s: write to read-only reg at offset 0x%"
	HWADDR_PRIx "\n", __func__, offset);
	break;
	case WDT_RELOAD_VALUE:
	s->regs[WDT_RELOAD_VALUE] = data;
	break;
	case WDT_RESTART:
	if ((data & 0xFFFF) == WDT_RESTART_MAGIC) {
	s->regs[WDT_STATUS] = s->regs[WDT_RELOAD_VALUE];
	awc->wdt_reload(s);
	}
	break;
	case WDT_CTRL:
	data = awc->sanitize_ctrl(data);
	enable = data & WDT_CTRL_ENABLE;
	if (enable && !aspeed_wdt_is_enabled(s)) {
	s->regs[WDT_CTRL] = data;
	awc->wdt_reload(s);
	} else if (!enable && aspeed_wdt_is_enabled(s)) {
	s->regs[WDT_CTRL] = data;
	timer_del(s->timer);
	} else {
	s->regs[WDT_CTRL] = data;
	}
	break;
	case WDT_RESET_WIDTH:
	if (awc->reset_pulse) {
	awc->reset_pulse(s, data & WDT_POLARITY_MASK);
	}
	s->regs[WDT_RESET_WIDTH] &= ~awc->ext_pulse_width_mask;
	s->regs[WDT_RESET_WIDTH] \|= data & awc->ext_pulse_width_mask;
	break;

	case WDT_RESET_MASK1:
	/* TODO: implement */
	s->regs[WDT_RESET_MASK1] = data;
	break;

	case WDT_TIMEOUT_STATUS:
	case WDT_TIMEOUT_CLEAR:
	case WDT_RESET_MASK2:
	case WDT_SW_RESET_CTRL:
	case WDT_SW_RESET_MASK1:
	case WDT_SW_RESET_MASK2:
	qemu_log_mask(LOG_UNIMP,
	"%s: uninmplemented write at offset 0x%" HWADDR_PRIx "\n",
	__func__, offset);
	break;
	default:
	qemu_log_mask(LOG_GUEST_ERROR,
	"%s: Out-of-bounds write at offset 0x%" HWADDR_PRIx "\n",
	__func__, offset);
	}
	return;
	}

	static const VMStateDescription vmstate_aspeed_wdt = {
	.name = "vmstate_aspeed_wdt",
	.version_id = 0,
	.minimum_version_id = 0,
	.fields = (const VMStateField[]) {
	VMSTATE_TIMER_PTR(timer, AspeedWDTState),
	VMSTATE_UINT32_ARRAY(regs, AspeedWDTState, ASPEED_WDT_REGS_MAX),
	VMSTATE_END_OF_LIST()
	}
	};

	static const MemoryRegionOps aspeed_wdt_ops = {
	.read = aspeed_wdt_read,
	.write = aspeed_wdt_write,
	.endianness = DEVICE_LITTLE_ENDIAN,
	.valid.min_access_size = 4,
	.valid.max_access_size = 4,
	.valid.unaligned = false,
	};

	static void aspeed_wdt_reset(DeviceState *dev)
	{
	AspeedWDTState *s = ASPEED_WDT(dev);
	AspeedWDTClass *awc = ASPEED_WDT_GET_CLASS(s);

	s->regs[WDT_STATUS] = awc->default_status;
	s->regs[WDT_RELOAD_VALUE] = awc->default_reload_value;
	s->regs[WDT_RESTART] = 0;
	s->regs[WDT_CTRL] = awc->sanitize_ctrl(0);
	s->regs[WDT_RESET_WIDTH] = 0xFF;

	timer_del(s->timer);
	}

	static void aspeed_wdt_timer_expired(void *dev)
	{
	AspeedWDTState *s = ASPEED_WDT(dev);
	uint32_t reset_ctrl_reg = ASPEED_WDT_GET_CLASS(s)->reset_ctrl_reg;

	/* Do not reset on SDRAM controller reset */
	if (s->scu->regs[reset_ctrl_reg] & SCU_RESET_SDRAM) {
	timer_del(s->timer);
	s->regs[WDT_CTRL] = 0;
	return;
	}

	qemu_log_mask(CPU_LOG_RESET, "Watchdog timer %" HWADDR_PRIx " expired.\n",
	s->iomem.addr);
	watchdog_perform_action();
	timer_del(s->timer);
	}

	#define PCLK_HZ 24000000

	static void aspeed_wdt_realize(DeviceState dev, Error *errp)
	{
	SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
	AspeedWDTState *s = ASPEED_WDT(dev);
	AspeedWDTClass *awc = ASPEED_WDT_GET_CLASS(dev);

	assert(s->scu);

	s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, aspeed_wdt_timer_expired, dev);

	/* FIXME: This setting should be derived from the SCU hw strapping
	* register SCU70
	*/
	s->pclk_freq = PCLK_HZ;

	memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_wdt_ops, s,
	TYPE_ASPEED_WDT, awc->iosize);
	sysbus_init_mmio(sbd, &s->iomem);
	}

	static Property aspeed_wdt_properties[] = {
	DEFINE_PROP_LINK("scu", AspeedWDTState, scu, TYPE_ASPEED_SCU,
	AspeedSCUState *),
	DEFINE_PROP_END_OF_LIST(),
	};

	static void aspeed_wdt_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);

	dc->desc = "ASPEED Watchdog Controller";
	dc->realize = aspeed_wdt_realize;
	dc->reset = aspeed_wdt_reset;
	set_bit(DEVICE_CATEGORY_WATCHDOG, dc->categories);
	dc->vmsd = &vmstate_aspeed_wdt;
	device_class_set_props(dc, aspeed_wdt_properties);
	dc->desc = "Aspeed watchdog device";
	}

	static const TypeInfo aspeed_wdt_info = {
	.parent = TYPE_SYS_BUS_DEVICE,
	.name = TYPE_ASPEED_WDT,
	.instance_size = sizeof(AspeedWDTState),
	.class_init = aspeed_wdt_class_init,
	.class_size = sizeof(AspeedWDTClass),
	.abstract = true,
	};

	static void aspeed_2400_wdt_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	AspeedWDTClass *awc = ASPEED_WDT_CLASS(klass);

	dc->desc = "ASPEED 2400 Watchdog Controller";
	awc->iosize = 0x20;
	awc->ext_pulse_width_mask = 0xff;
	awc->reset_ctrl_reg = SCU_RESET_CONTROL1;
	awc->wdt_reload = aspeed_wdt_reload;
	awc->sanitize_ctrl = aspeed_2400_sanitize_ctrl;
	awc->default_status = 0x03EF1480;
	awc->default_reload_value = 0x03EF1480;
	}

	static const TypeInfo aspeed_2400_wdt_info = {
	.name = TYPE_ASPEED_2400_WDT,
	.parent = TYPE_ASPEED_WDT,
	.instance_size = sizeof(AspeedWDTState),
	.class_init = aspeed_2400_wdt_class_init,
	};

	static void aspeed_2500_wdt_reset_pulse(AspeedWDTState *s, uint32_t property)
	{
	if (property) {
	if (property == WDT_ACTIVE_HIGH_MAGIC) {
	s->regs[WDT_RESET_WIDTH] \|= WDT_RESET_WIDTH_ACTIVE_HIGH;
	} else if (property == WDT_ACTIVE_LOW_MAGIC) {
	s->regs[WDT_RESET_WIDTH] &= ~WDT_RESET_WIDTH_ACTIVE_HIGH;
	} else if (property == WDT_PUSH_PULL_MAGIC) {
	s->regs[WDT_RESET_WIDTH] \|= WDT_RESET_WIDTH_PUSH_PULL;
	} else if (property == WDT_OPEN_DRAIN_MAGIC) {
	s->regs[WDT_RESET_WIDTH] &= ~WDT_RESET_WIDTH_PUSH_PULL;
	}
	}
	}

	static void aspeed_2500_wdt_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	AspeedWDTClass *awc = ASPEED_WDT_CLASS(klass);

	dc->desc = "ASPEED 2500 Watchdog Controller";
	awc->iosize = 0x20;
	awc->ext_pulse_width_mask = 0xfffff;
	awc->reset_ctrl_reg = SCU_RESET_CONTROL1;
	awc->reset_pulse = aspeed_2500_wdt_reset_pulse;
	awc->wdt_reload = aspeed_wdt_reload_1mhz;
	awc->sanitize_ctrl = aspeed_2500_sanitize_ctrl;
	awc->default_status = 0x014FB180;
	awc->default_reload_value = 0x014FB180;
	}

	static const TypeInfo aspeed_2500_wdt_info = {
	.name = TYPE_ASPEED_2500_WDT,
	.parent = TYPE_ASPEED_WDT,
	.instance_size = sizeof(AspeedWDTState),
	.class_init = aspeed_2500_wdt_class_init,
	};

	static void aspeed_2600_wdt_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	AspeedWDTClass *awc = ASPEED_WDT_CLASS(klass);

	dc->desc = "ASPEED 2600 Watchdog Controller";
	awc->iosize = 0x40;
	awc->ext_pulse_width_mask = 0xfffff; /* TODO */
	awc->reset_ctrl_reg = AST2600_SCU_RESET_CONTROL1;
	awc->reset_pulse = aspeed_2500_wdt_reset_pulse;
	awc->wdt_reload = aspeed_wdt_reload_1mhz;
	awc->sanitize_ctrl = aspeed_2600_sanitize_ctrl;
	awc->default_status = 0x014FB180;
	awc->default_reload_value = 0x014FB180;
	}

	static const TypeInfo aspeed_2600_wdt_info = {
	.name = TYPE_ASPEED_2600_WDT,
	.parent = TYPE_ASPEED_WDT,
	.instance_size = sizeof(AspeedWDTState),
	.class_init = aspeed_2600_wdt_class_init,
	};

	static void aspeed_1030_wdt_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	AspeedWDTClass *awc = ASPEED_WDT_CLASS(klass);

	dc->desc = "ASPEED 1030 Watchdog Controller";
	awc->iosize = 0x80;
	awc->ext_pulse_width_mask = 0xfffff; /* TODO */
	awc->reset_ctrl_reg = AST2600_SCU_RESET_CONTROL1;
	awc->reset_pulse = aspeed_2500_wdt_reset_pulse;
	awc->wdt_reload = aspeed_wdt_reload_1mhz;
	awc->sanitize_ctrl = aspeed_2600_sanitize_ctrl;
	awc->default_status = 0x014FB180;
	awc->default_reload_value = 0x014FB180;
	}

	static const TypeInfo aspeed_1030_wdt_info = {
	.name = TYPE_ASPEED_1030_WDT,
	.parent = TYPE_ASPEED_WDT,
	.instance_size = sizeof(AspeedWDTState),
	.class_init = aspeed_1030_wdt_class_init,
	};

	static void wdt_aspeed_register_types(void)
	{
	type_register_static(&aspeed_wdt_info);
	type_register_static(&aspeed_2400_wdt_info);
	type_register_static(&aspeed_2500_wdt_info);
	type_register_static(&aspeed_2600_wdt_info);
	type_register_static(&aspeed_1030_wdt_info);
	}

	type_init(wdt_aspeed_register_types)